1. Field of the Invention
The present invention relates to a liquid ejection head, an image forming apparatus and a liquid supply method for a liquid ejection head, and more particularly to a liquid ejection head in which high-density arrangement of nozzles can be achieved.
2. Description of the Related Art
There are inkjet recording apparatuses, which record desired images onto recording media by ejecting ink from liquid ejection heads (hereinafter referred to simply as “heads”) having a plurality of nozzles. The head has pressure chambers connected with the respective nozzles, and piezoelectric elements corresponding to these pressure chambers, and ink droplets are ejected from the nozzles by applying pressure to the ink inside the pressure chambers by means of the displacement of the piezoelectric elements.
Japanese Patent Application Publication No. 2002-19110, for example, discloses a head composed by layering together an elastic plate having pressure generating devices, a channel forming plate in which a plurality of long and thin pressure chambers (pressure generating chambers) are formed in parallel at a prescribed pitch, a connecting passage forming plate in which nozzle openings are formed in the side end faces, a reservoir forming plate in which a reservoir (common channel) which supplies ink to the respective pressure chambers, and a frame forming plate in which nozzle holes are formed in a row configuration.
Japanese Patent Application Publication No. 7-323541 discloses a head in which a channel forming plate having a plurality of slit-shaped channel holes, which are to be ink channels, formed at prescribed intervals, and a diaphragm made of a piezoelectric material, provided with electrodes opposing the channel holes on both the front and rear surfaces, are layered together alternately and fixed.
Japanese Patent Application Publication No. 2002-178509 discloses a head in which a plurality of piezoelectric bodies, each formed with a plurality of grooves, are layered together.
In recent years, there have been demands for inkjet recording apparatuses to be able to record high-resolution, high-definition images at high speed. For this purpose, it is necessary to arrange the nozzles of the head installed in the apparatus, at high density.
In the heads disclosed in the above-described Japanese Patent Application Publication Nos. 2002-19110, 7-323541 and 2002-178509, it is necessary to increase the number of layered members in order to achieve a high-density arrangement of the nozzles. However, in each of these heads, the ink tank is disposed to one side of the head, and if the number of layered members is increased, then the loss in the channel inside the head rises, and there is a problem in that refilling characteristics deteriorate.